QUALITY ASSURANCE IN HIGHWAY CONSTRUCTION: PART IV - VARIATIONS OF BITUMINOUS CONSTRUCTION

PROGRESS IS REVIEWED IN THE BUREAU OF PUBLIC ROADS RESEARCH PROGRAM FOR THE STATISTICAL APPROACH TO QUALITY ASSURANCE IN HIGHWAY CONSTRUCTION. TO DETERMINE THE QUALITY CHARACTERISTICS OF CURRENT CONSTRUCTION, MANY STATES HAVE BEEN MEASURING VARIATIONS IN ACCEPTED BITUMINOUS PRODUCTION. IT HAS BEEN FOUND THAT THE PRODUCTION OF HIGHWAY QUALITY BITUMINOUS PAVEMENT REQUIRES THE DILIGENCE OF THE PRODUCER, THE CONTRACTOR AND THE CONTRACTING AGENCY. THE STATISTICALLY MEASURED VARIATIONS OF ACCEPTED CONSTRUCTION INDICATE THAT MUCH MORE VARIABILITY EXISTS THAN IS REVEALED BY THE USUAL ACCEPTANCE TESTS. VARIATIONS IN EXCESS OF THOSE NORMALLY EXPECTED FOR GOOD PRACTICE WERE PREVALENT ON ALMOST EVERY JOB STUDIED. LARGE SAMPLING AND TESTING ERRORS VIRTUALLY PREVENT A TRUE EVALUATION OF THE MATERIAL VARIATION ON A SPECIFIC JOB. IT IS DIFFICULT TO ASSESS THE DEGREE TO WHICH VARIATIONS AFFECT ACTUAL PAVEMENT PERFORMANCE. RESEARCH RESULTS INDICATE THAT MUCH IMPROVEMENT COULD BE OBTAINED AND TESTING LOAD REDUCED BY THE FOLLOWING CHANGES: (1) ADJUST TOLERANCE LIMITS ON GRADATION TO CONFORM TO THE PRINCIPLE OF MOST TOLERANCE ON LARGEST FRACTION RETAINED ON A SIEVE, (2) CONTROL THE UNIFORMITY OF GRADATION OF THE MIXTURE BY HOT BIN SIEVE TESTS, WHEN A PRINTED RECORD OF BATCH WEIGHTS IS AVAILABLE, (3) REDUCE TO A MINIMUM THE NUMBER OF SIEVES USED FOR CONTROL TESTING, (4) EXERCISE MORE DILIGENCE IN THE TRAINING AND SURVEILLANCE OF OPERATORS PERFORMING CONTROL AND ACCEPTANCE TESTS, (5) REQUIRE INSTALLATION OF AUTOMATIC FEATURES ON ASPHALT PLANTS AND FINISHERS TO REDUCE HUMAN ERROR, AND (6) USE RANDOM SAMPLING TO OBTAIN ALL TEST PORTIONS.

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  • Supplemental Notes:
    • Vol 35, No 9 PP 201-211, 11 FIG, 9 TAB, 2 PHOT, 21 REF
  • Authors:
    • Granley, E C
  • Publication Date: 1969-8

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  • Accession Number: 00211445
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 29 1994 12:00AM